Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and in the zoo

Claire Gauquelin Des Pallieres; Paul E. Rose

doi:10.1371/journal.pone.0284221

Peer Review History

Original SubmissionNovember 4, 2022
13 Dec 2022 Decision Letter - Carlos Rouco, Editor PONE-D-22-30448Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and the zoo.PLOS ONE Dear Dr. Rose, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Jan 27 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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Please see the following video for instructions on linking an ORCID iD to your Editorial Manager account: https://www.youtube.com/watch?v=_xcclfuvtxQ 4. Please upload a new copy of Figure 4 as the detail is not clear. Please follow the link for more information: https://blogs.plos.org/plos/2019/06/looking-good-tips-for-creating-your-plos-figures-graphics/ https://blogs.plos.org/plos/2019/06/looking-good-tips-for-creating-your-plos-figures-graphics/ 5. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. Additional Editor Comments: Dear authors, Since it has been hard to find potential reviewers for the ms I did myself reviewed it. I think that is an original idea and method to survey and compare behaviours between wildlife and captive animals. However, I agree with the referee that this paper, in its current setup, may not give much information that is useful within zoos. I also agree with the referee that the discussion is over-reached – e.g. how this information can be used directly in terms of managing zoos? In addition, it is hard to compare the behaviour of wild animal, with captive ones, the latest have less predation risk, food availability, no harsh weather conditions, within others… I suggest authors to erect alternative hypotheses to their main conclusion, i.e. “The results suggest that these species benefit from increased perceived safety in larger groups, regardless of the species making up that group”, accounting for the main differences between wild and captive species behaviour. As rose by the referee, the way the data is presented in terms of combined zoo and wild data may be masking lots of differences, and it may be an error to join them together (due to the differences between the environments but principally the fact that zoos are keeping animals in pre-defined groups, these associations aren’t a choice). I would also encourage the authors to re-do the analyses with the two groups (zoo vs wild) as separate entities, and then compare them descriptively in the discussion. I would also encourage authors to look at fuller activity budgets rather than just vigilance. Authors should also state much clearly on the rationale for solely including vigilance since its application in zoos is relatively limited, especially as high levels of vigilance in the zoo environment it is not desirable. And finally, they should state much clearly, how their research may be useful or may be applied in zoos. Carlos Rouco Academic Editor [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Dear authors, Thank you for submitting this paper, I thought it was an interesting piece of work and is quite a nice idea in terms of understanding a little more about mixed species associations in the wild and considering how that can be transferred over to zoos. I did find some aspects of the work a little confusing and I think it needs some work to make the findings clearer and more applicable. My main comment is that I think you need to separate out the zoo and wild data for analysis. These two environments are so completely different that I think by combining them you are muddying the waters and I don’t think the conclusions hold valid because of it. The zoo is of course an enforced mixed species exhibit and an exhibit with no natural predators so is a completely different environment to the wild, and I think that is why they need to be treated separately. I am also unclear why you chose to focus only on vigilance, when you collected a whole activity budget. Vigilance is something we really drive hard not to have excessive amounts of in a zoo, and I think comparing whole activity budgets would be much more beneficial in terms of the aims of your study. General comments on methods: More detail needed on the zoo enclosure – approx. how big is the space and how much of that space was covered by the camera Habitat type is confusing, is this wild animals only? How are you defining different types of habitat within the zoo? L263/264: why did you use chi squared here? This data doesn’t appear to be categorical so a t-test or mann whitney would have been more appropriate Your factors in relation to ‘predicted likelihood of forming mixed social grps’ don’t make sense for zoos – the grps are formed by the zoo, there is nothing to predict it. you can look at whether they predict proximity but that is slightly different to what I think you are suggesting I don’t think within 6 body lengths is appropriate for a zoo setting – that’s a pretty large distance from another animal, I think you need a strong rationale for why you chose that and not for example within one or two body lengths as would normally be done You need details on number of grps where you did know the sexes of animals as the number of these will show whether your results in relation to this are affected by small samples Information needed on the zoo in terms of numbers of species/diversity of sp in the mixed sp enclosure General comments on discussion: Discussion feels a bit muddled and like it has lost its way a little bit – I think you need to split out zoo and wild data and then consider more what we can do with the wild data to help support zoo management decisions. I also think the discussion will be stronger if you look at activity budgets more fully. Line by line comments: L40: give examples of habitat type L47/48: I would argue that increased vigilance is not something L85: ‘have much potential’ is a bit clunky – suggest rewording L88: maybe, you can’t guarantee these risks can be avoided L92: enclosures L95: whether these associations change and if they influence… - you don’t know they definitely do – also, is this referring to zoo or wild? Needs clarity throughout on the two environments L108/109: typos L113: provide some examples of sp which are commonly kept in mixed sp grpings L115: in the wild? Zoo? L124: not sure how you are answering Q 3? L125: Q #4- you are forcing the sp associations within a zoo so I think this needs to refer to spatial associations L130: what do you mean by ‘particularly close proximity’? L134: six body lengths is huge in a zoo – needs strong rationale L134: if animals are forced to associate because of resources how do you know it is a choice to aggregate how they are? L149: you were only looking at vigilance so hypothesis #5 feels the opposite of hypothesis #4 L252: it is not clear if this is wild animals only, although I am not clear how it fits with the zoo environment, needs to specify L308: see comments above – I don’t think it makes sense to combine the data L310: not sure what is meant by ‘this was not significant for individual sp either’? L313: is this wild or zoo? need to clarify Tbl 5: make subtitles in the table bold so it’s clearer L380: not sure what the n=150 refers to? L381: you don’t know it is significantly influencing it – it stands to reason that larger grps will consist of more species but that’s not to say that correlation = causation here. Be mindful of this in interpretation through the discussion too. L397: how does this relate to zoos? L422 – 424: not sure how this has been reached from the data presented? L450: reduced vigilance as compared to what? Giraffe on their own? Or comparison to the wild? L458 – 461: it’s quite likely predators were just off camera. Predators in the wild are driving associations (amongst other things) so they’re a big driver of social grps L464 – 468: you haven’t included this information in your results – but I do think you need to L469 – 471: Yes! Which is what makes this study quite confusing L481: this is a strong rationale for analysing this data separately and only comparing where you have similar mixes between wild and zoo environments L528/529: they surely wouldn’t do it if it did create stress. There could be multiple other environmental reasons causing this. L530: how did sp diversity compare in zoo/wild? L537: why do they perform more vigilance? L550: needs a citation – not sure how/why this is considered more energetically costly than vigilance as a state behaviour? L576: how many grps are sexually dimorphic? How representative is this? L583: how does this compare with data from grps of ungulates L635: you could look at this with your data – and I would encourage you to look at this with your data L649: you only looked at vigilance L654 – 656: I don’t think you can say this as you’ve not really got any idea why vigilance reduced ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. 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Revision 1
1 Mar 2023 Author Response Replies to editor: Dear authors, Since it has been hard to find potential reviewers for the ms I did myself reviewed it. I think that is an original idea and method to survey and compare behaviours between wildlife and captive animals. However, I agree with the referee that this paper, in its current setup, may not give much information that is useful within zoos. I also agree with the referee that the discussion is over-reached – e.g. how this information can be used directly in terms of managing zoos? In addition, it is hard to compare the behaviour of wild animal, with captive ones, the latest have less predation risk, food availability, no harsh weather conditions, within others… I suggest authors to erect alternative hypotheses to their main conclusion, i.e. “The results suggest that these species benefit from increased perceived safety in larger groups, regardless of the species making up that group”, accounting for the main differences between wild and captive species behaviour. As rose by the referee, the way the data is presented in terms of combined zoo and wild data may be masking lots of differences, and it may be an error to join them together (due to the differences between the environments but principally the fact that zoos are keeping animals in pre-defined groups, these associations aren’t a choice). I would also encourage the authors to re-do the analyses with the two groups (zoo vs wild) as separate entities, and then compare them descriptively in the discussion. I would also encourage authors to look at fuller activity budgets rather than just vigilance. Authors should also state much clearly on the rationale for solely including vigilance since its application in zoos is relatively limited, especially as high levels of vigilance in the zoo environment it is not desirable. And finally, they should state much clearly, how their research may be useful or may be applied in zoos. Thank you for the comments. We are pleased that some aspects of this paper are deemed useful and we have been grateful for the opportunity for revisions. We have actioned all comments and edits by the reviewer and editor. Replies to reviewer 1 Reviewer #1: Dear authors, Thank you for submitting this paper, I thought it was an interesting piece of work and is quite a nice idea in terms of understanding a little more about mixed species associations in the wild and considering how that can be transferred over to zoos. I did find some aspects of the work a little confusing and I think it needs some work to make the findings clearer and more applicable. My main comment is that I think you need to separate out the zoo and wild data for analysis. These two environments are so completely different that I think by combining them you are muddying the waters and I don’t think the conclusions hold valid because of it. The zoo is of course an enforced mixed species exhibit and an exhibit with no natural predators so is a completely different environment to the wild, and I think that is why they need to be treated separately. I am also unclear why you chose to focus only on vigilance, when you collected a whole activity budget. Vigilance is something we really drive hard not to have excessive amounts of in a zoo, and I think comparing whole activity budgets would be much more beneficial in terms of the aims of your study. I have now separated out the analysis for zoo and wild data, and I have also included further information on a wider variety of behaviour types. General comments on methods: More detail needed on the zoo enclosure – approx. how big is the space and how much of that space was covered by the camera. I have added more information on the zoo enclosure. Habitat type is confusing, is this wild animals only? How are you defining different types of habitat within the zoo? It is used for both the zoo and the wild individuals and I have clarified this in the text and explained why it was also used in the zoo. L263/264: why did you use chi squared here? This data doesn’t appear to be categorical so a t-test or mann whitney would have been more appropriate I have re-phrased this paragraph to make more sense as a chi-squared test. Your factors in relation to ‘predicted likelihood of forming mixed social grps’ don’t make sense for zoos – the grps are formed by the zoo, there is nothing to predict it. you can look at whether they predict proximity but that is slightly different to what I think you are suggesting In the study I labelled a 'group' as being within six body lengths of each other, to differentiate animals that are just in the same area from animals that are potentially associating. I explained this in the methods but have also now clarified this further now so that it hopefully makes more sense. It is essentially about predicting proximity, as you suggest, as in the study my definition of a group is purely based on the extent of proximity between individuals. For example, whilst white white rhinoceroses and Thompson’s gazelles are both in the same enclosure, they were never observed to be anywhere near six body lengths from each other, and so were never labelled as being in the same group. I don’t think within 6 body lengths is appropriate for a zoo setting – that’s a pretty large distance from another animal, I think you need a strong rationale for why you chose that and not for example within one or two body lengths as would normally be done. I hope that my further detail on the size of the enclosure might help to explain why we felt that six body lengths was appropriate. You need details on number of grps where you did know the sexes of animals as the number of these will show whether your results in relation to this are affected by small samples. I have added information in the methods section and results. Information needed on the zoo in terms of numbers of species/diversity of sp in the mixed sp enclosure. I have added this information in the methods. General comments on discussion: Discussion feels a bit muddled and like it has lost its way a little bit – I think you need to split out zoo and wild data and then consider more what we can do with the wild data to help support zoo management decisions. I also think the discussion will be stronger if you look at activity budgets more fully. These changes have been made and the discussion is now more fluid. Line by line comments: L40: give examples of habitat type. I have provided examples. L47/48: I would argue that increased vigilance is not something. I have removed this section. L85: ‘have much potential’ is a bit clunky – suggest rewording. I have re-worded this sentence. L88: maybe, you can’t guarantee these risks can be avoided. I have re-worded to highlight this. L92: enclosures. Resolved. L95: whether these associations change and if they influence… - you don’t know they definitely do – also, is this referring to zoo or wild? Needs clarity throughout on the two environments. I have clarified this. L108/109: typos. Resolved. L113: provide some examples of sp which are commonly kept in mixed sp grpings I have added a relevant citation. L115: in the wild? Zoo? Re-phrased. L124: not sure how you are answering Q 3? I have re-worded this question to make more sense with the analysis done. L125: Q #4- you are forcing the sp associations within a zoo so I think this needs to refer to spatial associations. I felt that the location of the cameras near water sources in the wild locations created a somewhat similar situation to within the zoo enclosure, where animals are to some extent forced to use the same space (in the zoo because they are in an enclosure, and in the wild because they are all using the same resource), however I aimed to use the six body lengths to identify species that were closer than required even whilst using the same resource, both at the zoo and in the wild spaces. L130: what do you mean by ‘particularly close proximity’? I have clarified what is meant here by referring directly to the six body lengths measurement used. L134: six body lengths is huge in a zoo – needs strong rationale I have added details of the size of this San Diego Zoo enclosure. It is a large space, roughly 12 hectares in size, within which it is very easy for animals to stay at a significant distance to each other. Many species in this enclosure were never observed within six body lengths of each other. L134: if animals are forced to associate because of resources how do you know it is a choice to aggregate how they are? Please see response to comment L125. L149: you were only looking at vigilance so hypothesis #5 feels the opposite of hypothesis #4 I have now included analyses of additional behaviours rather than just looking at vigilance. H4 says that overall vigilance will be lower, but doesn’t suggest an impact of grouping, whereas H5 is focussing on the impact of grouping, and saying that vigilance may be even lower when in a mixed species group in captivity. L252: it is not clear if this is wild animals only, although I am not clear how it fits with the zoo environment, needs to specify Please see response to comment L134. The zoo enclosure is a very large space with a waterhole, areas of vegetative cover, and areas of open grass. L308: see comments above – I don’t think it makes sense to combine the data. I have changed the analyses to look at zoo and wild data separately. L310: not sure what is meant by ‘this was not significant for individual sp either’? I have re-worded this to be clearer. L313: is this wild or zoo? need to clarify Re-phrased. Tbl 5: make subtitles in the table bold so it’s clearer Done. L380: not sure what the n=150 refers to? I have clarified this. L381: you don’t know it is significantly influencing it – it stands to reason that larger grps will consist of more species but that’s not to say that correlation = causation here. Be mindful of this in interpretation through the discussion too. I have removed focal group size from the analysis as I realise it wasn't suitable. L397: how does this relate to zoos? Please see response to comment L134 & L252. L422 – 424: not sure how this has been reached from the data presented? Line deleted. L450: reduced vigilance as compared to what? Giraffe on their own? Or comparison to the wild? I have clarified this statement. L458 – 461: it’s quite likely predators were just off camera. Predators in the wild are driving associations (amongst other things) so they’re a big driver of social grps I have now removed the comment about the presence of predators not significantly influencing the associations and have made a comment about this limitation in the limitations section. L464 – 468: you haven’t included this information in your results – but I do think you need to I have now included additional information about general activity other than vigilance. L469 – 471: Yes! Which is what makes this study quite confusing I have tried to explain the way I was looking at associations and mixed species groupings more clearly, please see above my comments on six body lengths and this distinction of a group. L481: this is a strong rationale for analysing this data separately and only comparing where you have similar mixes between wild and zoo environments I have done this now. L528/529: they surely wouldn’t do it if it did create stress. There could be multiple other environmental reasons causing this. Noted. L530: how did sp diversity compare in zoo/wild? I have added information on this in the results and discussion. L537: why do they perform more vigilance? I have added an explanation for this. L550: needs a citation – not sure how/why this is considered more energetically costly than vigilance as a state behaviour? Comment removed after change to analyses. L576: how many grps are sexually dimorphic? How representative is this? I have added information on this in the methods and results. L583: how does this compare with data from grps of ungulates Re-phrased. L635: you could look at this with your data – and I would encourage you to look at this with your data. I didn't collect data on inter-species interactions, only intra-species interactions, as there was already a lot of data to collect and I found it easier to only have to focus on the behaviour of the focal species. L649: you only looked at vigilance We now include other behaviours. L654 – 656: I don’t think you can say this as you’ve not really got any idea why vigilance reduced Removed. Attachments Attachment Submitted filename: replies to editor and reviewers.docx https://doi.org/10.1371/journal.pone.0284221.r002
14 Mar 2023 Decision Letter - Carlos Rouco, Editor PONE-D-22-30448R1Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and in the zoo.PLOS ONE Dear Dr. Rose, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Apr 28 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Carlos Rouco, PhD Academic Editor PLOS ONE Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. Additional Editor Comments : Dear Authors, I have received now the comment from the reviewer and I am agree that the Ms has improved. I will recommend to you to follow all suggestions rose by reviewer, and pay special attention to the assertion left in the discussion (L651 – 653), which I don’t think you can state from your work, therefore I would encourage you to consider moving it away from discussing ‘trends’ in the data set, especially when you rightly recommended limitations in the analytical methods/the data. Carlos Rouco Academic Editor [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: (No Response) ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Dear authors, Thank you for taking the time to respond to my review and make subsequent modifications to the manuscript. I think the separation into zoo/wild has made it much easier to follow, and actually has led to some useful comparisons. I have just a few minor comments: L44: might be worth adding in a sentence about zoos here – i.e. maybe no impact because of the reduced need for animals to show heightened vigilance L291/292: why did you run the test for just some of the sp individually, I think this needs to be all or nothing, unless there is a strong rationale for just selecting some Table 3: you have four species here but at L291/292 you just said giraffe and waterbuck L532/533: I am not sure what this first sentence means L618: there is a word missing before ‘experiencing’, maybe ‘be’? L641 – 643: I don’t particularly think it is useful to discuss trends, as you don’t want people to take too much from it L264 – 265: is this another trend or is it statistically significant? L651 – 653: this feels like quite a strong assertion – especially given you have said a few lines before that males spent equal time in mixed and non-mixed groups. I’m concerned this comment might lead to even less interest in bachelor grps, whereas in actual fact we should be doing more than ever to make sure welfare of surplus males is good L669: remove ‘so’ L670 – 671: this sort of begs the question of why this analysis was done L689: is this section wild animals, or zoo animals, or both? Needs clarifying L691: what do you mean ‘particularly strong trends’? ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0284221.r003
Revision 2
19 Mar 2023 Author Response Editor comment I have received now the comment from the reviewer and I am agree that the Ms has improved. I will recommend to you to follow all suggestions rose by reviewer, and pay special attention to the assertion left in the discussion (L651 – 653), which I don’t think you can state from your work, therefore I would encourage you to consider moving it away from discussing ‘trends’ in the data set, especially when you rightly recommended limitations in the analytical methods/the data. Thank you for the comment. We are pleased that the manuscript is now improved. We have deleted the text in lines 651-653 and we have reviewed the discussion to ensure that trends and patterns are made clear and not passed off as significance. We have clarified sections of the discussion to remove ambiguity and ensured that figures are specifically linked to descriptions of the animals’ behaviour. Reviewer comment Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Thank you for taking the time to respond to my review and make subsequent modifications to the manuscript. I think the separation into zoo/wild has made it much easier to follow, and actually has led to some useful comparisons. Thank you for the useful and developmental feedback. We appreciate your time and effort in helping shape this manuscript into a more relevant piece of work. I have just a few minor comments: L44: might be worth adding in a sentence about zoos here – i.e. maybe no impact because of the reduced need for animals to show heightened vigilance Thank you for the useful edit. We have included this suggestion. L291/292: why did you run the test for just some of the sp individually, I think this needs to be all or nothing, unless there is a strong rationale for just selecting some Thank you for the comment. This was just the Chi squared for the number of times observed in mixed and single species groups for four example species that were seen in the wild and in the zoo and that may experience a markedly different social environment in the zoo (because of their wild ecology – group number and size, dispersal or distance between individuals) to check for any potential bias or outliers in the species under study. We have included further references to explain why these species were selected. Table 3: you have four species here but at L291/292 you just said giraffe and waterbuck Edited for clarity in the methods. L532/533: I am not sure what this first sentence means We have edited this section for clarity. L618: there is a word missing before ‘experiencing’, maybe ‘be’? Thank you for the correction. We have also edited this section for clarity. L641 – 643: I don’t particularly think it is useful to discuss trends, as you don’t want people to take too much from it We have re-written this as a call for more research to find out why this trend might occur. L264 – 265: is this another trend or is it statistically significant? We are not sure what you mean here as these lines are in the methods section? Please can this be clarified. L651 – 653: this feels like quite a strong assertion – especially given you have said a few lines before that males spent equal time in mixed and non-mixed groups. I’m concerned this comment might lead to even less interest in bachelor grps, whereas in actual fact we should be doing more than ever to make sure welfare of surplus males is good This, and the section in lines 641-643 have been completely re-written. If the reviewer is still unhappy, we can delete this section, but we feel it is worthwhile area of research extension to encourage others to look into. L669: remove ‘so’ Edited L670 – 671: this sort of begs the question of why this analysis was done We have clarified this section further. L689: is this section wild animals, or zoo animals, or both? Needs clarifying Edited for clarity. L691: what do you mean ‘particularly strong trends’? Removed and edited for clarity Attachments Attachment Submitted filename: PLoS One replies to reviewers.docx https://doi.org/10.1371/journal.pone.0284221.r004
27 Mar 2023 Decision Letter - Carlos Rouco, Editor Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and in the zoo. PONE-D-22-30448R2 Dear Dr. Rose, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Carlos Rouco, PhD Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0284221.r005
Formally Accepted
13 Apr 2023 Acceptance Letter - Carlos Rouco, Editor PONE-D-22-30448R2 Two’s company, three species is a crowd? A webcam-based study of the behavioural effects of mixed-species groupings in the wild and in the zoo Dear Dr. Rose: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Carlos Rouco Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0284221.r006

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